In this chapter, we will look at the techniques and methods that can be used to detect remote OSes. The vulnerabilities of operating systems are specific and inevitable. Consequently, it becomes important for network administrators to know about the operating system installed on all running hosts inside the network. For a small network, it might be easy to identify operating systems for all hosts. However, it becomes a  challenging job for large-scale cloud organizations to maintain a database where thousands of hosts are being deleted and created every minute and are therefore constantly changing. 

There are many scanning tools available on the market, but Nmap and Wireshark are the most popular and widely used tools. You should also have done some background reading in order to successfully use the Wireshark capture feature. In this chapter, we will use Nmap and Wireshark to run a scan and to capture packets. In the next chapter, we will discuss SSL, fundamental...